TM 5-3805-260-24adds to the pump oil in line (10) to elevator control valve(12). With the engine running at high rpm and the valvespool in control valve (12) in FORWARD position (C), theoil from pump (22) goes through line (7) to run elevatorhydraulic motor (1) forward at high speed. The oil fromthe elevator motor goes through line (8), control valve(12) and through return oil line (13) into filter and tank(19).Move the elevator speed lever to the LOW position andthe valve spool in elevator speed valve (6) moves toLOW SPEED position (L). Now, the oil from the coverend of pump (22) goes through speed valve (6) and goesinto return oil line (13) to the tank. With only oil from onesection of pump (22) to elevator motor (1), the elevatorruns at a slow speed.The elevator control lever must be moved to the HOLDposition to move the elevator valve spool to HOLDposition (B). With the valve spool in HOLD position, theoil from pump (22) goes through control valve (12),through return oil line (13) into filter and tank (19).Elevator Reverse (No Illustration)The elevator control lever is held in the REVERSEposition by the detent balls in elevator control valve (12).With the valve spool in REVERSE position (A), the oilfrom pump (22) goes through control valve ( 12) andthrough line (8) to elevator motor (1) to run the elevatorin reverse. The oil from the elevator goes through line(7), through control valve (12) and through return oil line(13) into the filter and tank (19). The reverse speed ofthe elevator is controlled by the rpm of the engine andthe position of the elevator speed lever connected to thevalve spool in elevator speed valve (6). HIGH SPEEDposition (H) lets the oil from the cover end section ofpump (22) add to the oil from the drive end section of thepump in line ( 10) to the elevator motor. The speed valvestem in LOW SPEED position (L) lets the oil from thecover end section of pump (22) go through return oil line(13) to the tank. Now, only the oil from the drive endsection of the pump goes through line (10) and to theelevator motor.Move the control lever to the HOLD position. This movesthe elevator valve spool to HOLD position (B) and stopsthe elevator.ELEVATOR VALVESControl ValveThe location of the elevator control valve is just in front oftransmission (2), near the left side of the machine. Theflexible cable from the control lever goes under thescraper hitch and is connected to valve spool (I) in theelevator control valve.ELEVATOR CONTROL VALVE1. Valve spool (in control valve). 2. Transmission.Detent balls, in the control valve, keep valve spool (1) inany of the three positions for the valve spool. When thevalve spool is held in FORWARD position (C), the oilfrom the pump goes in through inlet (6), opens checkvalve (7),- goes through the check valve and throughoutlet (4) that connects with an oil line to the elevatorhydraulic motor.ELEVATOR CONTROL VALVE (HOLD POSITION)1. Valve stem. 3. Outlet to tank. 4. Outlet to motor(for reverse). 5. Outlet to motor (for forward). 6. Inletfrom pump. 7. Check valve. A. REVERSE position. B.HOLD position. C. FORWARD position.With valve spool (1) in HOLD position (B), the pump oilthrough inlet (6) does not get any pressure to opencheck valve (7) because the oil goes out through outlet(3) and to the tank. The spring in check valve (7) keeps itclosed, when there is no pump oil pressure in the controlvalve, and the oil in the lines to the elevator motor isstopped. The hydraulic motor can not be turned when oilis stopped in the lines to the motor.With valve spool (1) in REVERSE position (A), the pumpoil through inlet (6) opens check valve (7) and then goesthrough outlet (5) that connects with an oil line to theelevator motor.4-20